// JavaScript Document
jQuery.extend({

  createUploadIframe: function (id, uri) {
    //create frame
    var frameId = 'jUploadFrame' + id;

    if (window.ActiveXObject) {
      var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');
      if (typeof uri == 'boolean') {
        io.src = 'javascript:false';
      }
      else if (typeof uri == 'string') {
        io.src = uri;
      }
    }
    else {
      var io = document.createElement('iframe');
      io.id = frameId;
      io.name = frameId;
    }
    io.style.position = 'absolute';
    io.style.top = '-1000px';
    io.style.left = '-1000px';

    document.body.appendChild(io);

    return io;
  },
  createUploadForm: function (id, fileElementId) {
    //create form 
    var formId = 'jUploadForm' + id;
    var fileId = 'jUploadFile' + id;
    var form = jQuery('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');
    var oldElement = jQuery('#' + fileElementId);
    var newElement = jQuery(oldElement).clone();
    jQuery(oldElement).attr('id', fileId);
    jQuery(oldElement).before(newElement);
    jQuery(oldElement).appendTo(form);
    //set attributes
    jQuery(form).css('position', 'absolute');
    jQuery(form).css('top', '-1200px');
    jQuery(form).css('left', '-1200px');
    jQuery(form).appendTo('body');
    return form;
  },

  ajaxFileUpload: function (s) {
    // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout  
    s = jQuery.extend({}, jQuery.ajaxSettings, s);
    var id = s.fileElementId;
    var form = jQuery.createUploadForm(id, s.fileElementId);
    var io = jQuery.createUploadIframe(id, s.secureuri);
    var frameId = 'jUploadFrame' + id;
    var formId = 'jUploadForm' + id;

    if (s.global && !jQuery.active++) {
      // Watch for a new set of requests
      jQuery.event.trigger("ajaxStart");
    }
    var requestDone = false;
    // Create the request object
    var xml = {};
    if (s.global) {
      jQuery.event.trigger("ajaxSend", [xml, s]);
    }

    var uploadCallback = function (isTimeout) {
      // Wait for a response to come back 
      var io = document.getElementById(frameId);
      try {
        if (io.contentWindow) {
          xml.responseText = io.contentWindow.document.body ? io.contentWindow.document.body.innerHTML : null;
          xml.responseXML = io.contentWindow.document.XMLDocument ? io.contentWindow.document.XMLDocument : io.contentWindow.document;

        } else if (io.contentDocument) {
          xml.responseText = io.contentDocument.document.body ? io.contentDocument.document.body.innerHTML : null;
          xml.responseXML = io.contentDocument.document.XMLDocument ? io.contentDocument.document.XMLDocument : io.contentDocument.document;
        }
      } catch (e) {
        jQuery.handleError(s, xml, null, e);
      }
      if (xml || isTimeout == "timeout") {
        requestDone = true;
        var status;
        try {
          status = isTimeout != "timeout" ? "success" : "error";
          // Make sure that the request was successful or notmodified
          if (status != "error") {
            // process the data (runs the xml through httpData regardless of callback)
            var data = jQuery.uploadHttpData(xml, s.dataType);
            if (s.success) {
              // ifa local callback was specified, fire it and pass it the data
              s.success(data, status);
            }
            ;
            if (s.global) {
              // Fire the global callback
              jQuery.event.trigger("ajaxSuccess", [xml, s]);
            }
            ;
          } else {
            jQuery.handleError(s, xml, status);
          }

        } catch (e) {
          status = "error";
          jQuery.handleError(s, xml, status, e);
        }
        ;
        if (s.global) {
          // The request was completed
          jQuery.event.trigger("ajaxComplete", [xml, s]);
        }
        ;


        // Handle the global AJAX counter
        if (s.global && !--jQuery.active) {
          jQuery.event.trigger("ajaxStop");
        }
        ;
        if (s.complete) {
          s.complete(xml, status);
        }
        ;

        jQuery(io).unbind();

        setTimeout(function () {
          try {
            jQuery(io).remove();
            jQuery(form).remove();

          } catch (e) {
            jQuery.handleError(s, xml, null, e);
          }

        }, 100);

        xml = null;

      }
      ;
    }
    // Timeout checker
    if (s.timeout > 0) {
      setTimeout(function () {

        if (!requestDone) {
          // Check to see ifthe request is still happening
          uploadCallback("timeout");
        }

      }, s.timeout);
    }
    try {
      var form = jQuery('#' + formId);
      jQuery(form).attr('action', s.url);
      jQuery(form).attr('method', 'POST');
      jQuery(form).attr('target', frameId);
      if (form.encoding) {
        form.encoding = 'multipart/form-data';
      }
      else {
        form.enctype = 'multipart/form-data';
      }
      jQuery(form).submit();

    } catch (e) {
      jQuery.handleError(s, xml, null, e);
    }
    if (window.attachEvent) {
      document.getElementById(frameId).attachEvent('onload', uploadCallback);
    }
    else {
      document.getElementById(frameId).addEventListener('load', uploadCallback, false);
    }
    return {
      abort: function () {
      }
    };

  },

  uploadHttpData: function (r, type) {
    var data = !type;
    data = type == "xml" || data ? r.responseXML : r.responseText;
    // ifthe type is "script", eval it in global context
    if (type == "script") {
      jQuery.globalEval(data);
    }

    // Get the JavaScript object, ifJSON is used.
    if (type == "json") {
      eval("data = " + data);
    }

    // evaluate scripts within html
    if (type == "html") {
      jQuery("<div>").html(data).evalScripts();
    }

    return data;
  }
});
